Intel 3945: wpi0 after some time stops working

[Vittorio De Martino]

Context: HP laptop DV6000, centrino duo, FreeBSD 7.0-BETA4

Following your advice I was able to start the intel 3945 card of my notebook 
and establish a WPA connection with the AP by way of the following script:
$$$$$$$$$$$$$$$$$$$$
wpa_supplicant -i wpi0 -c /etc/wpa_supplicant.conf -Bw
#ifconfig wpi0 up
dhclient wpi0
$$$$$$$$$$$$$$$$$$$$

Now, the consequent connection is steady for 10-20 minutes than it stops 
working (ifconfig wpi0 doesn't seem to signal anything wrong!) and I cannot 
connect to anything . Following 
your advice I set sysctl debug.wpi=-2 and copied an extract of the 
resulting, quite long, /var/log/messages into

http://www.de-martino.it/FreeBSD/log3945/log.txt

What's wrong with my 3945?

Ciao
Vittorio